1. Field of the Invention
The present invention relates generally to a receiver device suitable for receiving information transmitted over a satellite communication system. More particularly, the invention relates to a satellite communication system including a receiver device which ensures at least a minimum amount of data transmission even under unfavorable atmospheric conditions.
2. Description of the Prior Art
In the recent years, information transmission by means of satellite communication systems has become popular due to their speed and extensive range. Such satellite communication systems are known to be advantageous for transmitting information, such as video signals audio signals, data signals and so forth, to stations world-wide.
In satellite communication systems, information is converted into electromagnetic signals and transmitted to an artificial satellite from a transmitting station. The electromagnetic signals are modulated at a predetermined frequency and amplified for direct reception at receiving stations. Then, the signal are transmitted or distributed from the artificial satellite to the receiving stations. The electromagnetic signals used in satellite communication systems are sub-millimeter wave in the super-high frequency band. A super-high frequency signal is subject to significant absorption by mist, rain or so forth due to the short wavelength. Therefore, in conventional satellite communication systems, S/N ration decreases during heavy rain and other severe weather. In the worst case, transmitted information may be completely lost in the noise.
The present invention is intended to adapt receive devices for use in dual-mode data transmision systems.